(1. 中南大学粉末冶金国家重点实验室，长沙 410083；
2. 硬质合金国家重点实验室，株洲 412000；
3. 株洲硬质合金集团有限公司，株洲 412000)
摘 要: 为开发新型TiC基钢结硬质合金，采用Fe2Al5预合金粉末添加方式和普通液相烧结法制备不同Al含量(占粘结相含量的0、0.77%、1.54%、2.3%，质量分数)的TiC-65%(Fe-Cr-Mo-Al-C)钢结硬质合金。探讨Al含量对TiC-65%(Fe-Cr-Mo-Al-C)钢结硬质合金的组织与性能的影响规律；并考察Al含量对合金的烧结性、相种类及硬度的影响规律。结果表明：随Al含量的增加，Fe-C合金的包晶反应温度点降低，包晶反应区间、BCC铁素体区和低温区的κ-碳化物沉淀区扩大；合金的硬质相TiC形貌及分布相近，且Al主要是溶解在粘结相中；合金的铁磁性与粘结相中奥氏体数量有关，随Al含量的增加，淬火+回火态合金的硬度增加；其断裂韧性、抗弯强度在Al含量为1.54%时达到峰值。
关键字: TiC；钢结硬质合金；Fe-Al-C；组织；性能
（1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. State Key Laboratory of Cemented Carbide, Zhuzhou 412000, China;
3. Zhuzhou Cemented Carbide Group Co., Ltd., Zhuzhou 412000, China）
Abstract:In order to develop new TiC based steel bonded carbide，TiC-65%(Fe-Cr-Mo-Al-C) (mass fraction) hard alloys with different Al contents (with respect to binder phase contents of 0, 0.77%, 1.54%, 2.3%, mass fraction)were prepared by common liquid phase sintering method with addition of Fe2Al5prealloyed powder. The effects of Al contents on the microstructure and mechanical properties of TiC-65%(Fe-Cr-Mo-Al-C) alloys were explored. The effects of Al contents on the sinterability, phase species and hardness of alloys were investigated. The results show that, according to the calculated phase diagrams of the Fe-Al-C alloys, with the increase of Al content, the peritectic reaction temperature decreases and the intervals of peritectic reaction, BCC ferrite and low temperature region κ-carbide precipitation zone expand. With the increase of Al contents, the morphology and distribution of hard phase TiC are similar. Al dissolves into the binder phase. The ferromagnetic is connected with the amount of austeniteof binder phase. With the increase of Al content, the hardness of quenched and tempered alloys increases with the increase of Al content. And their fracture toughness and bending strength reach the peak values.
Key words: TiC; steel bonded carbide; Fe-Al-C; microstructure; property
